Watts is Watts

>Scott Corbeil asked about the heat of Metal Halide lights.
1) the heat thrown by X watts of MH light is the same as the heat
from X watts of FL lights. But you can easily have more watts of MH :)<

Pete Datcuk replied,

<<I would have to disagree with that statement.  I have never seen someone get
burned on a flourecent tube or an electronic ballast, but I assume that they
don't put fans on those MH enclosures for nothing!
    Just my two bits.>>

Don't confuse temperature with heat output.

Except the energy that is utilized by photysynthesis or goes out the window
as light, all the watts in are turned into heat.

The question is, what is the effiency of MH vs FL, how much light out per
watt in do you get?